IP Ratings Explained: Choosing the Right Protection Class for Your Lighting Project

What Does IP Rating Mean?

IP (Ingress Protection) rating is defined by international standard IEC 60529 and describes how well an electrical enclosure is protected against solid particles (dust) and liquids (water). Every luminaire intended for outdoor or wet/dusty environments should carry an appropriate IP rating.

Understanding the Two Digits

An IP rating consists of two digits: the first describes protection against solids, the second against liquids.

First Digit — Solid Particle Protection

Rating Protection Level
IP 4X Protected against solid objects >1mm (tools, wires)
IP 5X Dust protected (limited ingress, no harmful deposit)
IP 6X Dust tight (complete protection against dust)

Second Digit — Liquid Protection

Rating Protection Level
IPX3 Protected against spraying water (up to 60° from vertical)
IPX4 Protected against splashing water from any direction
IPX5 Protected against water jets
IPX6 Protected against powerful water jets
IPX7 Protected against temporary immersion (up to 1m, 30 min)
IPX8 Protected against continuous immersion (depth specified by manufacturer)

Which IP Rating for Which Application?

Application Recommended IP Reason
Indoor office / retail IP20–40 Dry environment, no water exposure
Bathroom / kitchen IP44–54 Splash protection required
Car park (covered) IP54–65 Dust and occasional water jets
Outdoor street / area IP65–66 Full dust protection + water jets
Industrial wash-down IP66–69K High-pressure cleaning
Underwater / fountains IP67–68 Submersion protection

IK Rating: Impact Protection

In addition to IP rating, luminaires in high-traffic or vandal-prone areas should also carry an IK rating (IEC 62262), which measures resistance to mechanical impact. IK08 (5 joules) is suitable for most public spaces; IK10 (20 joules) is recommended for high-risk environments.